Sql Server 2008 supports spatial data with new geometry and geography UDT's. They both support AsGml() method to serialize data in gml format. However they serialize data into GML3 format. Is there any way to tell it to serialize data into GML2 format?
As Marko said, there is no support for gml2 in Sql Server 2008, so I just ended up writing a function for transforming gml3 returned by the server to gml2 that I needed.